Piper touches a block of ice, and she feels that it is very cold. How does she feel the sensation of cold? A.
The nerves in the finger stop producing action potentials across synapses.
B.
The nerves in the finger detect stimuli and send the message to the brain.
C.
The nerves in the finger signal the arteries to stop circulation to the area.
D.
The nerves in the finger send a reflexive action through the spinal cord.

B. the nerves in the finger detect stimuli and send the message to the brain

d. the weight of the book

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.